refactor(psci): don't use PSCI_INVALID_PWR_LVL to signal OFF state

The target_pwrlvl field in the psci cpu data struct only stores the
highest power domain that a CPU_SUSPEND call affected, and is used to
resume those same domains on warm reset. If the cpu is otherwise OFF
(never turned on or CPU_OFF), then this needs to be the highest power
level because we don't know the highest level that will be off.

So skip the invalidation and always keep the field to the maximum value.
During suspend the field will be lowered to the appropriate value and
then put back after wakeup.

Also, do that in the suspend to standby path as well as it will have
been written before the sleep and it might end up incorrect.

Change-Id: I614272ec387e1d83023c94700780a0f538a9a6b6
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
4 files changed